The present invention relates to utility meter reading devices that can be accessed from a remote location in order to reduce the time and labor required to accurately record data from a customer""s meter.
In the distribution of such utilities as water, gas or electricity, mechanical meters have been employed to measure consumption of the utility at or near the customer""s site. To reduce the costs associated with reading such meters, efforts have been directed to modification or replacement of such meters with equipment that will allow remote access to the mechanical meter register in such a way that a determination of the amount of the utility that has been consumed can be made. While the replacement meters have proven useful, their expense has been a limitations on their implementation by utility suppliers particularly where the older mechanical meters continue to function correctly.
Incorporation of electronic reader devices into mechanical dial or disk meters has been attempted with some success but, again, care must be taken to avoid upsetting the register operation so as not to render the readings inaccurate. Typically, the installed mechanical type meters use a plurality of wheels such as is described in U.S. Pat. No. 3,806,904, which register units of a utility consumed in tens, hundreds, thousands, of units of the quantity used. Each wheel is divided into equal sections of ten units and the wheels are coupled where ten rotations of the tens wheels will cause one rotation of the hundreds wheel, etc. A segment scale or ladder is connected to each wheel to provide an electrical signal indicative of the position of its wheel and this readily converts to the quantity of die utility consumed. A receptacle is used to house a circuit board or wiring matrix that is accessible by reader device which records information stored in the receptacle as indicative of the position of its wheel and this readily converts to the quantity of the utility consumed.
Other prior art efforts are disclosed in U.S. Pat. Nos. 3,840,866 and 4,652,877.
The present invention avoids the drawbacks of the prior art by providing, in one form, a single chip micro-controller encoder that minimizes or eliminates the requirement common to the prior art of attaching cumbersome devices to the mechanical rotating disk type meter devices. Digit wheel sensing circuitry is provided that can be remotely activated to read the positions of the digit wheels of the mechanical meter so that the micro-controller can interpret the detected signals and communicate with a, meter reading device. Preferably, the micro-controller does not include a power source thus simplifying installation and maintenance. Further, the sensing is effected by inserting conductive members adjacent and attached to each digit wheel and cooperating stator discs sandwiched between each digit wheel pair. With this arrangement, alignment between a digit on the digit wheel and an associated conductive segment and a corresponding segment on the adjacent stator wheel will form a parallel plate capacitors. The second set of plates is at the center of the wheels and provides a return signal.
A meter reader is employed to activate the system and provide low level power to the system. The micro-controller directs an alternating current signal of 455 KHz sequentially to each of the ten stator board segments starting with the zero segment and ending with the xe2x80x9cninexe2x80x9d segment. Preferably, all the segments on the digit wheel segments are connected electrically together and driven with the 455 KHz signal simultaneously. Capacitive coupling between an aligned stator segment and a digit wheel segments will result in a transmitted signal pulse for each pair of stator and digit wheels through the wheel slip-ring segment to the stator slip-ring segment to create a coupling such as a slip ring capacitor to the micro-controller. The difference in amplitude or other characteristic of the transmitted signal will signify to the micro-controller alignment with the known stator position and thus an accurate measure of position and thereby consumption of the utility.